Systems and cognitive neuroscience depend on carefully designed and precisely implemented behavioral tasks to investigate neural phenomena. In most neuroscience laboratories, such tasks are implemented on a personal computer (PC) using software that is usually custom written by that lab for their specific needs, or by modifying preexisting software. Because many laboratories have developed separate solutions for their specific experiments, a modern, full-featured and flexible software solution is not currently available. The most commonly used software packages for controlling cognitive neuroscience experiments have become outdated due to their age, limited in their capabilities and flexibility, and difficult to use largely because of the requirement to construct behavioral tasks using low- level programming languages (e.g. C and C++) that are difficult to learn. To address these issues, we have developed a software system, called "Monkeylogic" (http://www.monkeylogic.net), that allows for straightforward coding and temporally-reliable execution of these tasks in Matlab, the most commonly used programming environment for data analysis in the neuroscience community. We find that Monkeylogic is capable of millisecond accuracy for presenting stimuli and measuring behavioral responses, and can control a wide range of behavioral tasks. Developing behavioral tasks is fast and easy compared to existing software solutions, and it runs on modern and inexpensive hardware and operating systems. Here, we propose to continue development of Monkeylogic in order to add the features necessary to make it the most comprehensive, flexible, and easy to use software solution for neurophysiological, psychophysical, and functional imaging studies of perception, cognition and behavior. Following the completion of this project, we intend to provide this software (along with the source code) free of charge to the scientific community with the hope that it will be a useful tool for a wide range of researchers. This software fills an important niche and satisfies and ever-growing demand for flexible software tools for controlling behavioral and sensory experiments. Thus, Monkeylogic will have a large positive impact on the ability of researchers to easily design and conduct studies aimed at understanding the brain mechanisms underlying perception, action and cognition. Due to its flexibility and large set of features, this software could be used by thousands of researchers across a wide range of behavioral and neuroscience disciplines. Furthermore, our intent to provide this software to the research community free of charge and with adequate documentation and support will maximize the impact and appeal of our software. PUBLIC HEALTH RELEVANCE: Systems and cognitive neuroscience depend on carefully designed and precisely implemented behavioral tasks to elicit the neural phenomena of interest. To facilitate this process, we have developed a software system that allows for the straightforward coding and temporally-reliable execution of these tasks in Matlab, a high-level programming language that is powerful, easy to use, and widely used in the behavioral and brain sciences. Our software has several advantages over existing systems including ease of use, compatibility with modern computer hardware and operating systems, low cost, and the ability to rapidly develop new behavioral paradigms. The goal of this project is to complete the development of this software system by adding critical features that are necessary for designing and controlling a wide range of behavioral, psychophysical and neurophysiological experiments.